"Comparing AmigaOS and RISC OS is an interesting exercise, especially when it provides inspiration for things like scripting languages, friendly internationalisation configuration, and transparent file format handling. However it also shows areas where RISC OS is grossly under-selling features we take for granted every day, but are seen as almost revolutionary elsewhere: For instance, being efficient on a sub-1GHz RISC CPU, anti-aliased fonts, supporting virtual disc labels, using a RAM-based temporary disc, and providing an iconbar."

"The [Amiga] OS also has an interesting system for allowing third-party software to interpret different file formats: An individual application does not have to understand how a particular file is structured, as it instead consults a separate program called a 'datatype' that operates on the file on the application's behalf."

1: Even though the format is open, implimenting, testing, and debugging an application's handling of that format still takes time. Instead of writing support for BMP, JPEG, PNG, GIF, etc. A developer could just write support for the Image datatype and automatically support all current formats and future ones as well.

2: If I understand the concept correctly, it works sort of like how video codecs work. Simply install a proprietary extention to the Image datatype and voila! All programs that support the Image dataytpe now support the proprietary format.

I always thought that the datatype system in AmigaOS was an awesome idea and I don't know why it hasn't caught on better. Is there a patent on it?

I notice on the linked site they talk a bit about RAMdisks. On the Amiga, vs. more primitive machines, the RAMdisk was a dynamic RAMdisk. That is, the disk was always the same size as whatever was in it (until you ran out of RAM). In DOS you had to set the size of the RAMdisk and it always took up that much memory whether it was empty or full. I don't know about other OSes but I think they were similar to DOS.

Nowadays most OSes use RAM as a dynamic HD cache which is kind of similar to the way AmigaOS used the RAMdisk anyway -- to speed up access to commonly used commands/data or as a point for temporary files.

The links in the article points to a list of touted advantages of AmigaOS 4, and suddenly I realised how much good ideas BeOS took from Amiga. In a way it's amazing to see several niche OSes implement a great idea like file-handlers (or whatchamacallem), yet frustrating to see the bigger OSes completely missing out on this.

Amiga had TWO different RAM disks - RAM: which was volatile and variable-sized, and RAD: which was recoverable and fixed-size. Back before computers had harddrives, I made my boot floppy so it copied the key system files to RAD:. I could then remove the floppy and the system could be rebooted from RAD: almost instantly (until you turned the power off).

Amiga had TWO different RAM disks - RAM: which was volatile and variable-sized, and RAD: which was recoverable and fixed-size. Back before computers had harddrives, I made my boot floppy so it copied the key system files to RAD:. I could then remove the floppy and the system could be rebooted from RAD: almost instantly (until you turned the power off).

Yeah... I remember that. I didn't use RAD: very much (except to test it once or twice).

Differences and similarities must be compared in this discussion between AmigaOS and RiscOS, and not with other systems like BeOS and MacOSX.

Well, first things that I can remember of two OSes (And amongst the most important ones):

1R) RiscOS is Posix (is it???) compatible, so almost any application from other OSes can be ported on it.

If I remember well, Firefox (for example) is already avaliable for Risc-OS.

1A) AmigaOS is not Posix compatible. It deals with fixed libraries and applications invoke these libraries at their wish.

For example Workbench GUI deals with Workbench.library.

Amiga still lacks of a Mozill/Firefox porting due to the fact that the functions of gecko engine, must FIRST be ported (or translated with similar funtions) on existing graphical engines of Amiga, and transformed into libraries objects (a library called gecko.library).

But, when such a translation work is completed, almost any Amiga application (even if not a browser, if it is well written) could invoke gecko.library and use its functions, gadgets and features.

For example Multiview, the all-purpose datatype based viewer of Amiga, with an available gecko.library, it could load and run any html page supported by gecko engine.

risc os is NOT posix compliant. it has some unix libs to help make it that way a little bit, but its not, out of the box, posix compliant at all. And the guy that did the firefox port has a lot of trouble with it iirc and it was very slow going.

> If you wanna try AmigaOS for free and better aimed at
> X86, try AROS (Amiga Research OS open source).

AROS is a nice effort, but IMO isn't ready for a comparison with AmigaOS3.1 (The OS which it originally tried to clone, but still an incomplete implemetation in this regard). AmigaOS3.1 is certainly at this point a lot more useful as it has far more software available. So IMO trying AmigaForever (Amiga OS3.9 emulation) or an enhanced OS3.1 emulation would give a more complete impression of what AmigaOS is actually like.

Just a thought:
I think KDEs KIOSlaves are a datatype-like concept. Of course they are not about supporting different file formats but they're doing the same thing for general I/O. Write an IOSlave for any protocol and magically all KIO aware applications can read and write files using that protcol.

AROS is open sourced and used to run on genuine Amiga computers and I am sure it is ported to other genuine Motorola 68k based systems as well. In addition AROS is ported to various PPC and x86 systems and x86-64 port is in progress.

Even if so, it's not available for 68k hardware currently to run any classic Amiga software. If it was people could use WinUAE/E-UAE/UAE in combination with AROS and wouldn't need to install classic 68k AmigaOS for that and I would add this information to my WinUAE tutorial.

The Amiga had a widely distributed free library called ixemul.library for posix support. It allowed most posix programs to be ported to the Amiga easily. What held back ports was not posix, but X Windows. There were only a couple X11 drivers for the Amiga, and they weren't very good or widely distributed.

Amiga had a third party multiuser library, but it wasn't used much as most Amigas were just used by one person. In fact, virtually all computers are still set up as single user. In more than 20 years, I've never set up a single computer to have more than one user, and never seen a single computer set for more than one user.

AROS does support the 68K processor, but almost no 68K systems. The only real 68K system currently in AROS is the old 68K PalmOS, and that hasn't been checked in quite some time and may no longer work right. It is thought 68K linux may work, but no one has tried it. There is a bounty for doing AROS in UAE as a replacement for an actual Amiga KS ROM.

AROS currently works in linux on PPC. I have Fedora Core 4 installed on my iMac, and AROS works on it nicely. There was work on a native PPC AROS on the Peg1 board, but that has since stopped.